Fabrication and characterization of CH3NH3(Cs)Pb(Sn)I3(Cl) perovskite solar cells with TiO2 nanoparticle layers

TiO2/CH3NH3(Cs)Pb(Sn)I-3(Cl)-based photovoltaic cells were fabricated and investigated. The solar cells with TiO2 nanoparticles on compact TiO2 layers provided better photovoltaic performance than those without TiO2 nanoparticles on the compact TiO2 layers. The short-circuit current density and open-circuit voltage were increased by using 16nm TiO2 nanoparticles, which resulted in improved photoelectric conversion efficiency. The external quantum efficiency increased because of the improved interface between the TiO2 layer and the perovskite layer. X-ray diffraction showed suppression of the formation of PbI2 crystals, and the coverage and grain boundary area of the perovskite crystals with 16nm TiO2 layers were improved, which resulted in the improved performance of the perovskite solar cell. (C) 2018 The Japan Society of Applied Physics